[Small cell lung cancer associated with paraneoplastic cerebellar degeneration and Lambert-Eaton myasthenic syndrome].

A 57-year-old man was admitted to our hospital in November 1997 because of dysarthria, progressive ataxia, generalized weakness, and incoordination in both hands. He had been aware of the dysarthria 6 months earlier. Chest roentgenograms and computed tomographic films disclosed a 5 cm x 6 cm mass in the left S3b. The patient was given a diagnosis of small cell lung cancer (T3N2M0, stage IIIA) associated with paraneoplastic cerebellar degeneration (PCD). Three courses of chemotherapy (carboplatin and etoposide) eliminated the tumor and slightly alleviated the PCD symptoms. In March 1998, electromyograms revealed a fall in the single-stimulated M wave and a waxing phenomenon that had not been observed on admission. Anti-P/Q type voltage gated calcium channel antibody was detected in serum samples obtained on admission and after chemotherapy. These findings confirmed an association with Lambert-Eaton myasthenic syndrome. No relapse of the tumor has been observed 15 months after the last course of chemotherapy.